Hey guys. I tried searching previous topics but didn't find anything specific to this. My apologies if this has already been discussed.

I've got a 1500 Tradesman that's throwing codes with a check engine light, and a "Check Fuel Cap" message on the dash. I replaced the fuel cap, to no avail. After that, I tried to take it to a local shop, and they said that there wasn't going to be any way to clear this without taking it to the dealer. They said they deal with this fault regularly and it simply won't go away without the dealership fixing it. I've made an appointment at my local dealership but it's not going to be for a while. I've tried to clear the codes with a code reader but it came right back. Before I fork out a bunch of money, is there anything else I can do to try to clear this? Thanks for your help!

 

It's also showing codes P0440 and P0456. Does that help diagnose it at all?

 

The two codes are talking about leaks in the evap system. Basically, the stuff that captures gas fumes, and burns them off, rather than vent them to atmosphere. The gas cap is a good place to start, but, if that doesn't fix it, time to have a look at ALL of the lines for the EVAP system. You got a leak somewhere.

 

It ended up being that Emissions System Integrity Module but I had to clear the codes and disconnect the battery to get it to clear. What a pain!

 

Thanks for the solution.